Add a folder for the external schemas to the repo with README

.gitignore

@@ -7,6 +7,7 @@ examples/**/failures.txt
 legacy/
 
 
+external_schema/*
 **/cloned_repos/**
 **/codemeta_results/**
 

external_schema/README.md

+In this folder you can put external schemas against which the data (json-ld) should be validated
+
+
+for example the schema.org schema:
+https://schema.org/version/latest/schemaorg-current-https.jsonld
+
+or the codemeta.json schema:
+https://doi.org/10.5063/schema/codemeta-2.0
+